The subject invention relates to a needleless connector referred to generally as a luer access device that allows a clinician to access a fluid flow line without the use of sharp needles. More particularly, the subject invention relates to a needleless luer access connector that may be opened by a standard male luer taper of a medical device, such as a syringe. The penetration of the connector by the male luer taper allows fluid flow through the connector. When the male luer taper is removed from the connector, it closes to prevent fluid flow therethrough.
In the treatment of patients, fluids are transferred between various containers and intravascular (IV) lines or through IV catheters into the patient through a closed system to prevent microbial ingress to the patient. During the course of such treatment where an IV catheter has been placed into a patient to gain access to the patient's vasculature, it may be necessary to infuse other fluids, such as medicaments, through the catheter into the patent or to withdraw blood from the patient for blood gas or other analysis. Such fluid withdrawal or injection into a patient may be through IV lines, saline wells, arterial lines, or hemodialysis lines. Previously, a rubber or silicone septum was used to cover an opening in the catheter or the IV line to prevent fluid from flowing out of the opening and to maintain a closed system. A clinician could access the opening by inserting a sharp needle from a syringe through the septum. This allowed the clinician to infuse fluid from the syringe into the patient or withdraw fluid from the patient into the syringe. The septum would reseal after the needle was withdrawn to prevent back flow of fluid.
In recent years, there has been great concern over the contamination of clinicians with a patient's blood or other fluid and a recognition that such “blood contaminated sharps” must be immediately disposed. This concern has arisen because of the advent of currently incurable and fatal diseases, such as Acquired Immune Deficiency Syndrome (“AIDS”) and hepatitis, which can be transmitted by the exchange of body fluids from an infected person to another person. Thus, contact with the body fluid of an AIDS or hepatitis infected person must be avoided to prevent the transmission of such diseases to a healthy person. If a needle has been used to access an IV line in communication with an AIDS or hepatitis infected person, the needle is a vehicle for the transmission of the disease. Although clinicians are aware of the need to properly handle “blood contaminated sharps”, unfortunately in certain medical environments, such as emergency situations or as a result of inattention or neglect, needlesticks with contaminated needles still occur. As a result of the problem of accidental needlesticks by “blood contaminated sharps”, much effort has been expended in developing various connectors that avoid the use of sharp needles.
One type of needleless connector includes a longitudinally movable diaphragm that controls the flow of fluid through an internal cannula fixed in the connector. This internal cannula defines the fluid flow path through the connector. The movable diaphragm cooperates with a biasing member such as a spring or other flexible member that biases the top of the movable diaphragm toward the inlet or proximal opening to the connector. The opening is typically in the form of a female luer connection. When the movable diaphragm is adjacent to the inlet of the connector, the movable diaphragm occludes the opening to the internal cannula to close the connector to fluid flow. The connector can be opened when the clinician inserts the male luer taper of another medical device, such as a syringe, into the female luer portion of the connector. When this is done, the movable diaphragm is pushed down into the housing so the internal cannula extends through a pre-formed slit in the movable diaphragm providing a fluid flow path through the connector.
Although such connectors can generally operate in accordance with their intended function, such connectors could be improved. When the tip of the internal cannula engages the movable diaphragm, the internal cannula has a tendency to core the movable diaphragm. This may cause pieces of the movable diaphragm to be broken off and potentially infused into a patient. In addition, this coring of the movable diaphragm promotes fluid leakage of the connector and can result in a pathway for microbial ingress. Finally, the force needed to move the movable diaphragm past the tip of the internal cannula could be quite high making it difficult to operate and resulting in a substantial kickback force that tends to push the male luer taper back out of the connector.
A potential improvement to connectors with internal cannula are connectors that include a longitudinally movable diaphragm having a molded in opening through the diaphragm to control the flow of fluid through the connector. Some biasing member biases the movable diaphragm toward the inlet of the device. In this position, the proximal portion of the movable diaphragm is radially biased by the sidewalls of the housing defining the inlet opening of the connector to bias closed the molded in opening. This prevents fluid flow through the connector. When the clinician inserts the male luer taper of the syringe into the inlet of the connector, the movable diaphragm is moved down into the connector to an area that does not contact the proximal portion of the movable diaphragm. This allows the proximal portion of the diaphragm to return to its unbiased condition with the molded in opening in the open position to provide a fluid flow through the connector. Thus, these connectors do not need an internal cannula to extend through the diaphragm to provide the fluid flow path through the connector.
However, connectors having a molded in opening are not without problems. For example, the molded in opening in the movable diaphragm may not be tightly closed when in the inlet. This could result in leakage through the connector and provide a path for microbial ingress. In addition, the high activation force and kick back problems are not resolved because of the biasing mechanism that is still used in these types of connectors.
Yet another approach has been the development of a connector that can be accessed by a blunt cannula that is connected to the standard male luer taper of a standard syringe. Such a connector has a septum having a longitudinal slit extending through it disposed over an opening on a proximal end of the connector. The distal end of the connector includes a standard male luer taper so the connector can be connected to other medical devices and IV lines having a female luer connection. This type of connector cannot be accessed with a standard male luer taper because a standard male luer taper is too large to fit into the space in the opening not already occupied by the septum. Instead this type of connector is accessed by a blunt cannula that is narrower than a standard male luer taper and which can be attached to a standard male luer taper. When the clinician desires to access the medical device or IV line, a blunt cannula is placed on the syringe and is then inserted through the slit in the septum. This places the syringe in fluid communication with the medical device or IV line. After fluid is injected into or withdrawn from the patient, the syringe with the blunt cannula is removed from the septum. Because of the design of the connector, the slit in the septum closes and prevents the backflow of fluid through the device.
Although slit septum connectors that can be accessed by a blunt cannula work generally in accordance with their intended purpose they could be improved. For example, this type of connector requires that a separate blunt cannula be connected to the male luer taper of another medical device to allow the connector to be accessed. This requires excess inventory problems and adds costs to the health care facility using the connector. Moreover, the blunt cannula typically does not fill up the space in the housing of the connector when it is accessed. This leaves an annular “dead space” cavity in the housing between the sides of the blunt cannula and the inner walls of the housing. Residual blood may be left in this cavity and provide a breeding ground for various germs and microbes and is difficult to flush.